Data Zone
Justification of Red List category
Although this species is confined to a single island, it is not believed that the species approaches the thresholds for listing as Vulnerable under the range size criterion (Extent of Occurrence <20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population is considered to be stable, and hence does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size remains small, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
Using distance sampling, Baker et al. (1996) estimated a population of 393-764 individuals of T. ruficollaris, believed to represent a depleted population due to habitat loss and degradation. In 2018-2019, using a similar method, Thacker et al. (2022) estimated 3,191-5,283 individuals (equivalent to c.2,100-3,500 mature individuals), with densities (0.12-1.65 birds/ha) similar to those of other Pacific Todiramphus. Although the population density and area of suitable habitat between the two periods appear to have genuinely increased, Baker et al. (1996) are considered likely to have underestimated the number of T. ruficollaris in secondary habitats due to their exclusion of agricultural habitat in their calculation, despite Thacker et al. (2022) finding T. ruficollaris at a relatively high density in this habitat. Similarly, Baker et al. (1996) did not survey either the central plantation forest or village areas for T. ruficollaris (see also Rowe and Empson 1996), whereas Thacker et al. (2022) found the species present in both areas, with densities in plantation forest very similar to those of primary forest. Consequently, the number of mature individuals is considered best represented by the estimation made by Thacker et al. (2022), and is placed here between 2,100 and 3,500, with a best estimate of 2,700.
Trend justification
The species is believed to be currently stable or increasing (Thacker et al. 2022). It formerly declined, principally owing to the widespread cultivation of pineapples. Following the collapse of the industry in the 1980s, the pineapple plantations on the volcanic hills were replaced by plantation forest. In contrast, the land used for the cultivation of pineapples in the lowlands was left to regenerate into secondary forest. These left the extent of primary and Barringtonia forests to increase slightly (from 11.2 km2 to 13.1 km2, and 1.94 km2 to 3.0 km2 respectively) between 1996 and 2019, and the area of secondary forest more substantially, from 4.0 km2 to 12.9 km2 (see Thacker et al. [2022] for discussion on why the 1996 values, from Baker et al. [1996], may not be directly comparable). These have led to a population recovery from 390-760 individuals in 1996 (Baker et al. [1996], although this is likely to have been a potentially substantial underestimate) to 3,200-5,300 in 2018-19 (Thacker et al. 2022). The island is currently suspected to be at carrying capacity for the habitat available, although further restoration of forest may increase the population further (however there may be balance shifts in this with, for example, primary forests hosting lower densities than secondary forest).
Todiramphus ruficollaris is endemic to Mangaia, Cook Islands.
Occurs in a range of habitat types from sea level to 1,300 m (Quintero and Jetz 2018) including (densities in parentheses): Barringtonia forest (70/km2), primary forest (72/km2), secondary forest (165/km2), plantation forest (67/km2) and around villages (12/km2) (Thacker et al. 2022). It feeds on insects, grubs, cockroaches and spiders, with lizards forming an important part of the diet (Pratt et al. 1987, Rowe and Empson 1996b). It nests in tree-cavities (preferring coconut and Barringtonia asiatica). The clutch-size is 2-3 (Pratt et al. 1987, Rowe and Empson 1996b).
The introduced Common Myna Acridotheres tristis (numbering c.9,000 birds), found in villages, horticultural areas, secondary forest and small forest tracts, competes for food and harasses breeding birds causing nest failure (Rowe and Empson 1996a, G. McCormack in litt. 2007). In a previous study of 10 kingfisher nests in disturbed forest, 11 young were raised from seven nests; Mynas were the cause of failure in one nest and were thought responsible for the failure of the other two (G. McCormack in litt. 2007). However, it has been found that the kingfisher is unexpectedly common in disturbed habitat where the Myna is abundant and a recent study concluded that the mynas are unlikely to be causing population reductions and may be instead negatively impacted by ongoing habitat regeneration (Thacker et al. 2022). Cats and rats, both Pacific rat Rattus exulans and black rat R. rattus, are present in all forest-types (particularly prevalent in areas with a high abundance of coconut trees) and are potential predators (Baker et al. 1996, Rowe and Empson 1996a). Long-tailed Koel Urodynamis taitensis, a winter migrant from New Zealand, may also predate eggs and chicks (Rowe and Empson 1996a). Clearance for agriculture and browsing by goats cause habitat loss and forest fragmentation, whilst pigs affect forest regeneration (Rowe and Empson 1996a); however, overall, the island's forests have been regenerating in spite of these threats.
Conservation Actions Underway
In 1996, a baseline survey and vegetation and rat-trapping studies were conducted. In 1997, this was followed by the first simple census using the Distance Sampling method, and this was repeated in 2018-2019 (Kelly and Bottomley 1998, Thacker et al. 2022). The feasibility of the eradication of Common Myna from the island was assessed in 2006, it was concluded that it was possible, at a cost of NZ$100,000 (Parkes 2006) however numbers of mynas have probably increased since (Thacker et al. 2022). Aage V Jensen Charity Foundation of Denmark is supporting BirdLife Cook Island’s partner Te-Ipukarea-Society in creating a site support group for the island, establishing a community led management plan and to raise awareness of this species among the community, including the creation of a documentary to be aired on national TV (Te-Ipukarea-Society 2016).
19 cm. Chunky kingfisher with big bill. Greenish-blue crown, cheeks, and upperparts, bluest on wings and tail. Rest of plumage pale. Eyebrow and collar strongly tinged rufous or ochre. Voice Series of alternating short and long "mewing" notes.
Text account compilers
Mahood, S., Stattersfield, A., Berryman, A.
Contributors
Karika, I., McCormack, G. & Pilgrim, J.
Recommended citation
BirdLife International (2024) Species factsheet: Mangaia Kingfisher Todiramphus ruficollaris. Downloaded from
https://datazone.birdlife.org/species/factsheet/mangaia-kingfisher-todiramphus-ruficollaris on 24/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 24/12/2024.